Combustion section having primary burner and set of secondary burners

Abstract

A turbine engine has a compressor section, a combustion section, and a turbine section in a serial flow arrangement along an engine centerline. The combustion section has: a primary combustor liner comprising an inner liner and an outer liner; and a dome wall extending between the inner liner and the outer liner. A primary combustor having a primary combustion chamber at least partially defined by an inner liner, an outer liner, and a domed wall, and having a primary combustor height and at least one small combustor having a secondary combustion chamber having a small combustor height.

Description

Technical Field

[0001] The present subject matter relates generally to a combustion section of a turbine engine and, more particularly, to a combustion section having a primary combustor and a secondary combustor. Background Art

[0002] The turbine engine is driven by the flow of combustion gases through the engine to rotate a plurality of turbine blades, which in turn rotate the compressor, thereby providing compressed air to the combustor for combustion. The combustor may be disposed within the turbine engine and fluidly coupled to the turbine into which the combustion gases flow.

[0003] It is known to use hydrocarbon fuels in the combustors of turbine engines. Typically, air and fuel are fed into a combustion chamber, the air is mixed with the fuel, and the fuel is then burned in the presence of the air to produce hot gases. The hot gases are then fed into a turbine where they are cooled and expanded to produce power. The byproducts of the combustion of the fuel typically include byproducts that are harmful to the environment, such as nitrogen oxides and nitrogen dioxide (collectively referred to as NO x ), carbon monoxide (CO), unburned hydrocarbons (UHC) (e.g., methane and volatile organic compounds that contribute to the formation of atmospheric ozone), and sulfur oxides (e.g., SO 2 and SO 3 ) other oxides.

[0004] Various fuels are being explored for combustion turbine engines. Hydrogen or hydrogen mixed with another element or compound can be used for combustion, however hydrogen or hydrogen mixed fuels can result in higher flame temperatures than traditional fuels. That is, hydrogen or hydrogen mixed fuels generally have a wider flammable range and faster burning speed than traditional fuels (such as petroleum-based fuels, or petroleum and synthetic fuel mixtures).

[0005] Standards stemming from global air pollution issues regulate NOx generated by turbine engine operation. x , UHC and CO emissions. In particular, NO is formed in the burner due to the high burner flame temperature during operation. x It is expected that NOx can be reduced by adjusting the temperature distribution and / or flame pattern within the burner. x emissions while still maintaining desired efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] In the attached picture:

[0007] Figure 1 It is a schematic diagram of a turbine engine.

[0008] Figure 2 Depicts a combustion section of a turbine engine having a set of secondary burners including annular small burners Figure 1A cross-sectional view along line II-II.

[0009] Figure 3 Depicts the primary burner and a portion of the annular small burner in the combustion section. Figure 2 A cross-sectional view taken along line III-III.

[0010] Figure 4 According to the aspects disclosed herein Figure 3 A variation of a cross-sectional view of FIG.

[0011] Figure 5 According to another aspect disclosed herein Figure 3 Another variation of a cross-sectional view of FIG.

[0012] Figure 6 According to the aspects disclosed herein Figure 2 A variation of a cross-sectional view of FIG.

[0013] Figure 7 As seen from line VII Figure 6 Schematic diagram of a portion of the outer liner of the combustion section.

[0014] Figure 8 It is the outer lining of the combustion section. Figure 7 A variation of the schematic diagram.

[0015] Fig. 9 It is the outer lining of the combustion section. Figure 7 A variation of the schematic diagram. DETAILED DESCRIPTION

[0016] The disclosed aspects described herein relate to combustion sections, in particular, combustion sections having primary burners and secondary burners. For illustrative purposes, the present disclosure will be described with respect to a turbine engine. However, it will be understood that the disclosed aspects described herein are not limited thereto, and the combustion sections described herein can be implemented in engines (including but not limited to turbojets, turboprops, turboshafts, and turbofans). The disclosed aspects discussed herein can be in non-aircraft engines with burners, such as in other mobile applications and non-mobile industrial, commercial, and residential applications, and have general applicability.

[0017] As used herein, the word "exemplary" means "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, unless expressly stated otherwise, all embodiments described herein are to be considered exemplary.

[0018] As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another, and are not intended to indicate the position or importance of each component.

[0019] The terms "front" and "rear" refer to relative positions within a gas turbine engine or vehicle and refer to the normal operating attitude of the gas turbine engine or vehicle. For example, for a gas turbine engine, front refers to a position closer to the engine inlet, while rear refers to a position closer to the engine nozzle or exhaust.

[0020] As used herein, the term "upstream" refers to the direction opposite to the direction of fluid flow, while the term "downstream" refers to the direction in the same direction as the direction of fluid flow. The terms "forward" or "front" mean in front of something, and "rearward" or "rear" mean behind something. For example, when used in relation to fluid flow, forward / front may mean upstream, and rearward / rear may mean downstream.

[0021] The term "fluid" may be a gas or a liquid. The terms "fluid coupling" and "fluidly coupled" refer to the ability of a fluid to establish a connection between designated areas.

[0022] Furthermore, as used herein, the term "radial" or "radially" refers to directions away from a common center. For example, in the overall context of a turbine engine, radial refers to directions along a ray extending between a central longitudinal axis of the engine and an outer periphery of the engine.

[0023] All directional references (e.g., radial, axial, proximal, distal, upper, lower, upward, downward, left, right, transverse, front, rear, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, forward, backward, etc.) may be used for identification purposes to help the reader understand the present disclosure and do not create limitations, particularly limitations on the position, orientation, or use of the disclosed aspects described herein. Connection references (e.g., attachment, coupling, connection, and engagement) may be used and will be interpreted broadly and may include intermediate structural elements between sets of elements and relative movement between elements unless otherwise indicated. Therefore, a connection reference does not necessarily mean that two elements are directly connected and fixed relative to each other. The exemplary drawings are for illustration purposes only, and the dimensions, positions, orders, and relative sizes reflected in the attached drawings may vary.

[0024] Unless the context clearly dictates otherwise, the singular forms "a," "an," and "the" include plural references. Also, as used herein, the term "set" or "a group of" elements may include any number of elements, including only one.

[0025] Approximate language as used in the entire specification and claims herein is applied to modify any quantitative representation that can allow variation without causing its related basic function to change. Therefore, the value modified by one or more terms such as "approximately", "approximately", "substantially" and "substantially" is not limited to the specified precise value. In at least some cases, the approximate language may correspond to the accuracy of the instrument used to measure the value, or the accuracy of the method or machine used to construct or manufacture parts and / or systems. In at least some cases, the approximate language may correspond to the accuracy of the instrument used to measure the value, or the accuracy of the method or machine used to construct or manufacture parts and / or systems. For example, approximate language may refer to 1%, 2%, 4%, 5%, 10%, 15% or 20% of the end point of a single value, a range of values ​​and / or a range of limited values. Here and throughout the specification and claims, range restrictions are combined and interchanged, and such ranges are identified and include all sub-ranges contained therein, unless otherwise indicated by context or language. For example, all ranges disclosed herein include endpoints, and the endpoints can be combined independently of each other.

[0026] Figure 1 is a schematic diagram of a turbine engine 10. As a non-limiting example, the turbine engine 10 may be used within an aircraft. The turbine engine 10 may include at least a compressor section 12, a combustion section 14, and a turbine section 16. A drive shaft 18 rotationally couples the compressor section 12 and the turbine section 16 so that rotation of one affects rotation of the other, and defines an axis of rotation or centerline 20 of the turbine engine 10.

[0027] The compressor section 12 may include a low pressure (LP) compressor 22 and a high pressure (HP) compressor 24 that are serially fluidly coupled to each other. The turbine section 16 may include an LP turbine 26 and an HP turbine 28 that are serially fluidly coupled to each other. The drive shaft 18 may operably couple the LP compressor 22, the HP compressor 24, the LP turbine 26, and the HP turbine 28 together. Alternatively, the drive shaft 18 may include an LP drive shaft (not shown) and an HP drive shaft (not shown). The LP drive shaft may couple the LP compressor 22 to the LP turbine 26, and the HP drive shaft may couple the HP compressor 24 to the HP turbine 28. The LP spool may be defined as a combination of the LP compressor 22, the LP turbine 26, and the LP drive shaft, such that the rotation of the LP turbine 26 may apply a driving force to the LP drive shaft, which in turn may rotate the LP compressor 22. The HP spool may be defined as a combination of the HP compressor 24, the HP turbine 28, and the HP drive shaft, such that the rotation of the HP turbine 28 may apply a driving force to the HP drive shaft, which in turn may rotate the HP compressor 24.

[0028] The compressor section 12 may include a plurality of axially spaced stages. Each stage includes a set of circumferentially spaced rotating blades and a set of circumferentially spaced fixed vanes. The compressor blades for one stage of the compressor section 12 may be mounted to a disk that is mounted to the drive shaft 18. Each set of blades for a given stage may have its own disk. The vanes of the compressor section 12 may be mounted to a casing that may extend circumferentially around the turbine engine 10. It should be understood that the representation of the compressor section 12 is merely schematic and there may be any number of stages. Further, it is contemplated that there may be any other number of components within the compressor section 12.

[0029] Similar to the compressor section 12, the turbine section 16 may include a plurality of axially spaced stages, with each stage having a set of circumferentially spaced rotating blades and a set of circumferentially spaced stationary vanes. The turbine blades for one stage of the turbine section 16 may be mounted to a disk, which is mounted to the drive shaft 18. Each set of blades for a given stage may have its own disk. The vanes of the turbine section 16 may be mounted to the housing in a circumferential manner. It is noted that there may be any number of blades, vanes, and turbine stages, as the illustrated turbine section is merely a schematic representation. Further, it is contemplated that there may be any other number of components within the turbine section 16.

[0030] The combustion section 14 may be disposed in series between the compressor section 12 and the turbine section 16. The combustion section 14 may be fluidly coupled to at least a portion of the compressor section 12 and the turbine section 16 such that the combustion section 14 at least partially fluidly couples the compressor section 12 to the turbine section 16. As a non-limiting example, the combustion section 14 may be fluidly coupled to the HP compressor 24 at an upstream end of the combustion section 14 and fluidly coupled to the HP turbine 28 at a downstream end of the combustion section 14.

[0031] During operation of the turbine engine 10, ambient or atmospheric air is drawn into the compressor section 12 via a fan (not shown) upstream of the compressor section 12, where the air is compressed, defining pressurized air. The pressurized air may then flow into the combustion section 14, where it is mixed with fuel and ignited, thereby generating combustion gases. The HP turbine 28 extracts some work from these combustion gases, which drives the HP compressor 24. The combustion gases are exhausted into the LP turbine 26, which extracts additional work to drive the LP compressor 22, and the exhaust gases are ultimately exhausted from the turbine engine 10 via an exhaust section (not shown) downstream of the turbine section 16. The drive of the LP turbine 26 drives the LP spool to rotate the fan (not shown) and the LP compressor 22. The pressurized airflow and the combustion gases may together define a working airflow through the fan, compressor section 12, combustion section 14, and turbine section 16 of the turbine engine 10.

[0032] Figure 2 The combustion section 14 is depicted along Figure 1 1-1, which defines a transverse plane (denoted as "TP"). The combustion section 14 may include an annular arrangement of primary fuel injectors 30 disposed around the centerline 20 of the turbine engine 10. Each primary fuel injector 30 is fluidly coupled to a primary combustor 32. It should be understood that the annular arrangement of fuel injectors may be one or more fuel injectors, and one or more primary fuel injectors 30 may have different characteristics. Depending on the type of engine in which the primary combustor 32 is located, the primary combustor 32 may have a can shape, a can annular or annular arrangement. In a non-limiting example, an annular arrangement is shown and disposed within a casing 36. The primary combustor 32 is defined by a primary combustor liner 38, which includes an outer liner 40 and an inner liner 42 that are concentric relative to each other and annularly around the centerline 20. The dome wall 44, together with the primary combustor liner 38, defines a primary combustion chamber 46 annularly around the centerline 20. A compressed air passage 70 may surround the primary combustor 32 and be at least partially defined by the casing 36.

[0033] The combustion section 14 also includes a set of secondary burners 50, which includes an annular small burner 34. As used herein, "small" means that the component referenced by the term small is smaller than a corresponding similar component without the term small (i.e., the annular small burner 34 is smaller than the primary burner 32). The annular small burner 34 is defined by a secondary burner liner 52 that is concentric with respect to the outer liner 40 and the inner liner 42 and annularly surrounds the centerline 20. The secondary burner liner 52, together with the outer liner 40, defines at least a portion of a secondary combustion chamber 54 that is circumferentially arranged around the centerline 20. The annular small burner 34 opens into the primary burner 32. More specifically, the secondary burner liner 52 terminates at an end 57 axially downstream of the primary fuel injector 30.

[0034] The primary burner 32 generates a primary exhaust gas (indicated as “G1”) in the primary combustion chamber 46. The set of secondary burners 50 generates a secondary exhaust gas (indicated as “G2”) in the secondary combustion chamber 54 that flows into the primary combustion chamber 46. The secondary exhaust gas G2 circulates in the primary combustion chamber 46 to form a secondary combustion chamber 54. 2 The level is insufficient and reduces the temperature in the primary combustion chamber 46. This causes NO x Reduction of emissions.

[0035] Figure 3 Depicted along Figure 2The cross-sectional view taken along line III-III of FIG. 1 shows the combustion section 14 viewed in a radial plane (denoted as "RP"). As can be seen more clearly, the annular small burner 34 leads to the primary burner 32. The primary burner 32 is connected to the turbine section 16 ( Figure 1 ) and a primary burner outlet 48 of the secondary combustor 46. The dome assembly 60 includes a dome wall 44 and accommodates a primary fuel injector 30. The primary fuel injector 30 can be fluidly coupled to a fuel inlet 62 via a fuel passage 64, which can be suitable for receiving a primary fuel flow (indicated as "F1"). The primary fuel injector 30 can terminate at a fuel outlet (also referred to herein as a dome inlet 66). In some embodiments, the primary fuel injector 30 can include a swirler 68 arranged circumferentially around the dome inlet 66. The primary igniter 61 is fluidly coupled to the primary combustion chamber 46. The rear wall 51 extends radially from the end 57 to connect the secondary combustor liner 52 to the outer liner 40. The secondary combustor liner 52 terminates at an end 57 downstream of the dome inlet 66.

[0036] A set of primary dilution openings 77 may be located downstream of the annular mini-combustor 34 in the outer liner 40 and the inner liner 42 . It is further contemplated that the set of dilution openings 77 may be located anywhere, including upstream of the annular mini-combustor 34 .

[0037] The annular small burner 34 includes at least one small dome assembly 80, at least one small dome assembly 80 includes a small dome wall 82 and accommodates a small fuel injector 84. At least one small dome assembly 80 can be a plurality of dome assemblies arranged circumferentially around the annular small burner 34. The small fuel injector 84 can be fluidly connected to a secondary fuel passage 86, and the secondary fuel passage 86 can be suitable for receiving a secondary fuel flow (denoted as "F2"). The small fuel injector 84 terminates at a secondary fuel outlet (also referred to herein as a small dome inlet 88 leading to the secondary combustion chamber 54). Although shown as radially aligned, it is envisioned that the small dome inlet 88 is circumferentially staggered relative to the dome inlet 66. In some embodiments, the small fuel injector 84 may include a swirler (not shown). It is further envisioned that the group of secondary burners does not include a swirler, but may have a non-swirling air channel. The secondary igniter 63 is fluidly connected to the secondary combustion chamber 54.

[0038] The dome inlet 66 defines a first centerline (designated as “CL1”). The mini-dome inlet 88 defines a second centerline (designated as “CL2”) extending toward the primary combustion chamber 46. The first centerline CL1 and the second centerline CL2 intersect to define a first primary combustor angle (designated as “α 1 ”). As shown in the figure, the first primary burner angle α 1The small dome inlet 88 may also be angled so that the first primary burner angle α 1 The range is 90° to 165°.

[0039] The primary burner length (designated as "L1") is measured between the dome wall 44 and the primary burner outlet 48 parallel to the first centerline CL1. The primary combustion zone 72 is defined as the volume between the dome wall 44 and the second centerline CL2. The primary combustion length (designated as "L M ”) is measured parallel to the first centerline CL1 from the dome wall 44 to the second centerline CL2. The main combustion length L M It is 5% to 90% of the primary burner length L1. The main combustion length L M It may be 5% to 70%, 5% to 50%, or 5% to 40% of the primary burner length L1.

[0040] The primary combustion chamber 46 has a radial dimension extending from the liner 42 to the secondary combustor liner 52 and is referred to herein as the primary combustor height (denoted as "H"). The primary combustor height H may be measured proximate the dome wall 44. The separation line (denoted as "S L ”) extends axially from the end 57 parallel to the first centerline CL1 at the primary burner height H. The separation line S L The primary combustion chamber 46 is separated from the secondary combustion chamber 54 .

[0041] Small burner height (expressed as "H M ”) is defined as the radial dimension extending from the secondary combustor liner 52 to the outer liner 40. The amount by which the rear wall 51 extends radially toward the small dome inlet 88 is equal to the small combustor height H M . Small burner height H M From 0.0H to 0.6H. In other words, the small burner height H M The measured value is an amount up to and including 60% of the primary burner height H.

[0042] Small burner height H M Maintain separation line S L and the outer liner 40 to define a small combustion zone 74. The small combustion zone 74 is radially spaced outward from the main combustion zone 72 and axially downstream of the main combustion zone 72.

[0043] During operation, compressed air (indicated as “C”) may be drawn from compressor section 12 ( Figure 1) is provided to the combustion section 14. The compressed air C may be split between the primary combustor 32 and the set of secondary combustors 50 such that the primary combustor 32 receives 60% to 90% of the compressed air C from the compressor section 12, while the set of secondary combustors 50 receives between 10% and 40% of the compressed air C.

[0044] Compressed air C may be fed into the primary fuel injector 30 and mixed with the primary fuel flow F1 to define a primary fuel / air mixture (denoted as "FA1"). The primary fuel injector 30, together with the primary igniter 61, defines a primary combustion system having a primary flame. The primary fuel injector 30 may distribute a premixed or partially premixed primary fuel / air mixture FA1. In addition, the fuel flow F1 may be a diffusion fuel that does not contain an air mixture before entering the primary combustion chamber 46.

[0045] The primary combustion system can be a rich burn system or a lean burn system. A rich burn system includes a fuel / air ratio that is higher than the stoichiometric fuel / air ratio, while a lean burn system includes a fuel / air ratio that is lower than the stoichiometric fuel / air ratio. A rich burn system for the primary burner 32 will produce higher temperatures within the primary combustion chamber 46, thereby providing flame stability for the entire combustion system. When combined with a lean burn system for the set of secondary burners 50, NO is reduced from the secondary combustion chamber 54. x .

[0046] Similarly, the primary burner 32 may be used to reduce NO from the primary combustion chamber 46. x A lean-burn system is provided in which the set of secondary burners 50 has a rich-burn system for providing flame stability to the primary burners 32 and the entire combustion system.

[0047] The compressed air C may be fed into the small fuel injector 84 and mixed with the secondary fuel flow F2 to define a secondary fuel / air mixture (indicated as "FA2"). The small fuel injector 84 together with the secondary igniter 63 may define a small combustion system including a secondary flame that may be premixed, partially premixed, or diffused. The small combustion system may be a rich burn system or a lean burn system. The fuel provided to the primary fuel injector 30 and the small fuel injector 84 may include injection fuel natural gas or a more reactive fuel such as H 2 and H 2 In some embodiments, the turbine engine 10 can be started on conventional fuel using the set of secondary burners 50, wherein the secondary exhaust gas G2 ( Figure 2 ) propagates toward the primary combustion chamber 46, which can use conventional fuel or H 2 Fuel to provide fuel.

[0048] In addition, both the primary burner 32 and the set of secondary burners 50 can be either rich or lean systems. Since both have lean systems, NO x Emissions are greatly reduced. However, at least one or more of the primary fuel injectors 30 or the mini-fuel injectors 84 will need to be fuel-rich to provide flame stability. Likewise, both the primary burner 32 and the set of secondary burners 50 can have a rich-burning system, wherein reducing the NO x The O in the primary burner 32 is made by staging the fuel and the products released from the group of secondary burners 50. 2 Insufficient NO x To achieve.

[0049] When the secondary exhaust gas G2 is directed to the primary combustion chamber 46, the primary exhaust gas G1 ( Figure 2 ) and the secondary exhaust gas G2, which reduces the O in the primary combustion chamber 46 2 levels, thereby reducing NO x Fuel staging between the primary combustion chamber 46 and the secondary combustion chamber 54 reduces the fuel / air ratio in these stages of the combustion section 14, which helps to further reduce temperatures and NO x In contrast, a single-stage burner will have a relatively high fuel / air ratio and higher temperatures, which results in higher NO x emission.

[0050] The combustion residence time of the main combustion zone 72 can be in the range of 2 ms to 8 ms, including the end points. The combustion residence time of the small combustion zone 74 can be in the range of 0.1 ms to 2 ms, including the end points. The total combustion residence time of the combustion section 14 can be in the range of 2 ms to 10 ms, including the end points.

[0051] The equivalence ratio of the primary burner 32 may be 0.5 to 2, inclusive. The equivalence ratio of the annular mini-burner 34 may be 0.4 to 2, inclusive.

[0052] Figure 4 A cross-sectional view of another embodiment of the combustion section 114 is depicted as viewed in a radial plane (denoted as "RP"). The combustion section 114 is similar to Figure 3 therefore, like parts will be identified by like numerals increased by 100, it being understood that the description of like parts of the combustion section 14 applies to the combustion section 114 unless otherwise stated.

[0053] Primary combustor 132 is disposed within casing 136 and is fluidly connected to turbine section 16 at dome wall 144. Figure 1) extends between a primary burner outlet 148 of the primary burner 132. The outer liner 140 is radially spaced from the inner liner 142 to define a primary combustion chamber 146 of the primary burner 132. The dome assembly 160 includes a dome wall 144 and accommodates a primary fuel injector 130. The primary fuel injector 130 can be fluidly coupled to a fuel inlet 162 via a fuel passage 164, which can be suitable for receiving a primary fuel flow (indicated as "F1"). The primary fuel injector 130 can terminate at a fuel outlet (also referred to herein as a dome inlet 166). In some embodiments, the primary fuel injector 130 may include a swirler 168 arranged circumferentially around the dome inlet 166. The primary igniter 161 is fluidly coupled to the primary combustion chamber 146. At least one opening 157 extends through the outer liner 140 and is located downstream of the dome inlet 66.

[0054] A set of dilution openings 177 may be located downstream of the at least one opening 157 in the inner liner 142. It is further contemplated that the primary combustor liner 138 may include any number of dilution openings 177 at any location, including upstream of the at least one opening 157 and within the outer liner 140.

[0055] The combustion section 114 also includes a set of secondary burners 150, which includes at least one annular small burner 134. At least one small burner 134 includes a secondary burner liner 152 that defines a secondary combustion chamber 154. At least one small burner 134 includes a small dome assembly 180, which includes a small dome wall 182 and accommodates a small fuel injector 184. The small fuel injector 184 can be fluidly coupled to a secondary fuel passage 186, which can be suitable for receiving a secondary fuel flow (denoted as "F2"). The small fuel injector 184 terminates in a secondary fuel outlet (also referred to herein as a small dome inlet 188 leading to the secondary combustion chamber 154). The secondary combustion chamber 154 is fluidly coupled to the primary combustion chamber 146 at at least one opening 157 to define a secondary burner outlet 158. In some embodiments, the small fuel injector 184 may include a low swirl number swirler 189, i.e., having a number less than 1 and having a low tangential velocity, arranged circumferentially around the small dome inlet 188. It is further contemplated that at least one small burner 134 does not include a swirler, but may have a non-swirl air passage. The secondary igniter 163 is fluidly coupled to the secondary combustion chamber 154.

[0056] It is contemplated that at least one of the small burners 134 includes a gradually converging body 176. The gradually converging body 176 is defined as a portion of the at least one small burner 134 wherein a first cross-sectional area (designated as "CA1") proximate the small dome inlet 188 is greater than a second cross-sectional area (designated as "CA2") proximate the secondary burner outlet 158.

[0057] A set of secondary dilution openings 178 may be provided in the secondary combustor liner 152 for connecting the compressed air passage 170 and the secondary combustion chamber 154. As a non-limiting example, when the primary combustor 132 is a rich combustion system, the set of secondary dilution openings 178 is located at a rear position of at least one small combustor 134 for shaping the combustor exit temperature distribution and mode factor associated with at least one small combustor 134 and the primary combustor 132.

[0058] The outer liner 140 defines a primary combustor height H of the primary combustor 132 proximate the dome wall 144 and measured radially between the inner liner 142 and the outer liner 140 .

[0059] Small burner height H M Defined as the radial dimension extending from the outer liner 140 to the small dome wall 182. Small combustor height H M From 0.0H to 0.6H. In other words, the small burner height H M The measured value is an amount up to and including 60% of the primary burner height H.

[0060] The secondary combustor liner 152 defines a small combustion zone 174 . The small combustion zone 174 is radially and axially spaced from the primary combustion zone 172 .

[0061] The dome inlet 166 defines a first centerline CL1. The mini-dome inlet 188 defines a second centerline CL2 extending toward the secondary burner outlet 158. The secondary burner outlet 158 ​​intersects the second centerline CL2 to define a geometric center 190 of the secondary burner outlet 156. The first centerline CL1 and the second centerline CL2 intersect to define a second primary burner angle (denoted as “α”) in the radial plane RP. 2 ”). The at least one small burner 134 may be angled toward the primary burner outlet 148 such that the second primary burner angle α 2 When angled toward the primary burner outlet 148, at least one small burner 134 has a second primary burner angle α that can vary from 90° to 165°. 2 .

[0062] At the second primary burner angle α 2 The process of directing the secondary exhaust gas G2 from the at least one small burner 34 into the primary combustion chamber 46 increases the turbulence level. In addition, the gradually converging body 176 accelerates the secondary fuel / air mixture FA2 exiting the secondary burner outlet 158 ​​into the primary combustion chamber 146, which further increases the turbulence level. The turbulence helps to thoroughly mix the primary exhaust gas G1 and the secondary exhaust gas G2, which improves the uniform temperature distribution, again resulting in NOx reduction.

[0063] Figure 5 A cross-sectional view of yet another embodiment of a combustion section 214 viewed in a radial plane (denoted as "RP") is depicted. The combustion section 214 is similar to Figure 4 thus, like parts will be identified by like numerals increased by 100, it being understood that the description of like parts of the combustion section 114 applies to the combustion section 214 unless otherwise stated.

[0064] Primary combustor 232 is connected to turbine section 16 at dome wall 244 and fluidly coupled thereto. Figure 1 ) extends between the primary burner outlet 248 of the dome assembly 260. The outer liner 240 is radially spaced from the inner liner 242 and together define a primary burner liner 238. The primary burner liner 238 defines at least a portion of the primary combustion chamber 246 of the primary burner 232. The dome assembly 260 includes a dome wall 244 and accommodates a primary fuel injector 230. The primary fuel injector 230 can be fluidly coupled to the fuel inlet 262 via a fuel passage 264, which can be suitable for receiving a primary fuel flow (indicated as "F1"). The primary fuel injector 230 can terminate at a fuel outlet, which is also referred to herein as a dome inlet 266 and is located in the dome assembly 260. In some embodiments, the primary fuel injector 230 can include a swirler 268 arranged circumferentially around the dome inlet 266. The primary igniter 261 is fluidly coupled to the primary combustion chamber 246. At least one opening 257 extends through the outer liner 240 and is located downstream of the dome inlet 266.

[0065] A set of dilution openings 277 may be located in the outer liner 240, upstream of the mini-dome inlet 288, or in the inner liner 242. It is further contemplated that the primary combustor liner 238 may include any number of dilution openings in any location, including in the outer liner 240, downstream of the mini-dome inlet 288, and in the inner liner 242.

[0066] The combustion section 214 also includes a set of secondary burners 250, which includes at least one small burner 234. At least one small burner 234 includes a secondary burner liner 252 that defines a secondary combustion chamber 254. At least one small burner 234 includes a small dome assembly 280, which includes a small dome wall 282 and accommodates a small fuel injector 284. The small fuel injector 284 can be fluidly coupled to a secondary fuel passage 286, which can be suitable for receiving a secondary fuel flow (denoted as "F2"). The small fuel injector 284 terminates at a secondary fuel outlet (also referred to herein as a small dome inlet 288 leading to the secondary combustion chamber 254). In some embodiments, the small fuel injector 284 may include a low swirl number swirler 289 arranged circumferentially around the small dome inlet 288, that is, having a number less than 1 and having a low tangential velocity. It is further contemplated that at least one of the small burners 234 does not include a swirler, but may have a non-swirling air passage. The secondary igniter 263 is fluidly coupled to the secondary combustion chamber 254. The secondary igniter 263 is fluidly coupled to the secondary combustion chamber 254.

[0067] The dome inlet 266 defines a first centerline CL1. The mini-dome inlet 288 may define a second centerline CL2 extending toward the secondary burner outlet 258. The secondary burner outlet 258 intersects the second centerline CL2 to define a geometric center 290 of the secondary burner outlet 258. The at least one mini-burner 234 may have a constant area cross-section between the mini-dome inlet 288 and the secondary burner outlet 258 along the second centerline CL2.

[0068] A set of secondary dilution openings 278 may be provided in the secondary combustor liner 252 for connecting the compressed air passage 270 and the secondary combustion chamber 254. As a non-limiting example, when the primary combustor 232 is a rich combustion system, the set of secondary dilution openings 278 is located at a rear position of the at least one small combustor 234 for shaping the combustor exit temperature distribution and mode factor associated with the at least one small combustor 234 and the primary combustor 232.

[0069] The secondary combustor liner 252 defines a small combustion zone 274 . The small combustion zone 274 is radially and axially spaced from the primary combustion zone 272 .

[0070] The secondary burner outlet 258 intersects the second centerline CL2 to define a geometric center 290 of the secondary burner outlet 258. The first centerline CL1 and the second centerline CL2 intersect to define a third primary burner angle (denoted as “α 3 ”). At least one small burner 234 can be oriented orthogonally to the primary burner 232 so that the third primary burner angle α3 is 90°.

[0071] Figure 6 A cross-sectional view of the combustion section 314 is depicted. The combustion section 314 is Figure 2 thus, like parts will be identified by like numerals increased by 300, it being understood that the description of like parts of combustion section 14 applies to combustion section 314 unless otherwise stated.

[0072] The combustion section 314 may include an annular arrangement of primary fuel injectors 330 disposed around a centerline 320 of the turbine engine 10. Each of the primary fuel injectors 330 is fluidly coupled to a primary burner 332. It should be understood that the annular arrangement of the fuel injectors may be one or more fuel injectors, and one or more of the primary fuel injectors 330 may have different characteristics. Depending on the type of engine in which the primary burner 332 is located, the primary burner 332 may have a can shape, a can annular or annular arrangement. In a non-limiting example, an annular arrangement is shown and disposed within a casing 336. The primary burner 332 is defined by a primary burner liner 338, which includes an outer liner 340 and an inner liner 342 that are concentric relative to each other and annularly around the centerline 320. The dome wall 344, together with the primary burner liner 338, defines a primary combustion chamber 346 that annularly surrounds the centerline 320.

[0073] The combustion section 314 also includes a set of secondary burners 350, which includes a circumferential arrangement of a plurality of discrete small burners 334. Each discrete small burner 334 in the set of secondary burners 350 is defined by a secondary burner liner 352 extending generally vertically from the primary burner liner 338. The secondary burner liner 352 defines at least a portion of a secondary combustion chamber 354 circumferentially spaced about the centerline 320. The set of secondary burners 350 is fluidly coupled to the primary burner 332 by at least one opening 357 extending through the outer liner 340. More specifically, the secondary combustion chamber 354 terminates at the at least one opening 357 to define a secondary burner outlet 358. In a non-limiting example, each secondary combustion chamber 354 in the set of secondary burners 350 is radially aligned with the primary fuel injector 330.

[0074] The primary burner 332 generates a primary exhaust gas (indicated as “G1”) in the primary combustion chamber 346. The group of secondary burners 350 generates a secondary exhaust gas (indicated as “G2”) in the secondary combustion chamber 354, and the secondary exhaust gas flows into the primary combustion chamber 346. The secondary exhaust gas G2 circulates in the primary combustion chamber 346 to make the primary combustion chamber 346 2 The level is insufficient and reduces the temperature in the primary combustion chamber 346. This causes NO x Reduction of emissions.

[0075] It should be understood that any of the plurality of discrete small burners 334 may include a plurality of discrete small burners 334 as previously described herein. Figure 4 The gradually converging body 176 described. In addition, as Figure 5 As shown, any of the plurality of discrete small burners 334 may have a constant area cross section throughout. It is further contemplated that any combination of converging and constant area cross section burner bodies may be contemplated.

[0076] Figure 7 is from Figure 6 Schematic diagram of a portion of the outer liner 340 as seen along line VII-VII in FIG. The axial direction (denoted as "AD") is parallel to the engine centerline 20 ( Figure 1 ), a radial direction (denoted as "RD") extends into the page and is perpendicular to the axial direction AD, and a circumferential direction (denoted as "CD") is perpendicular to the radial direction RD and the axial direction AD. The circumferential direction CD surrounds the engine centerline and extends up and down the page when oriented in two dimensions as shown in the figure.

[0077] At least one opening 357 is a plurality of openings 357a, 357b, 357c. Each opening 357a, 357b, 357c is defined in relation to the group of secondary burners 350 ( Figure 6 ) in each small burner 334 ( Figure 6 ) corresponding secondary burner outlet 358. In one aspect, the plurality of openings 357a, 357b, 357c are located at the same axial position and are aligned along the circumferential direction CD.

[0078] Figure 8 According to another aspect disclosed herein Figure 7 Schematic diagram of a variation of a portion of the outer liner 340 of FIG. The at least one opening 457 is a plurality of openings 457a, 457b, 457c located within the outer liner 440, each of which defines a secondary combustor outlet 458. The plurality of openings 457a, 457b, 457c are axially spaced apart from each other in the axial direction AD and are not aligned in the circumferential direction CD. The first opening 457a is axially spaced apart from the second opening 457b by a first amount (denoted as “S1”). The third opening 457c is axially spaced apart from the second opening 457b by a second amount (denoted as “S2”). The second opening 457b may be located downstream of the first opening 457a and the third opening 457c. The third opening 457c may be located downstream of the first opening 457a and upstream of the second opening 457b.

[0079] Fig. 9 According to another aspect disclosed herein Figure 7Schematic diagram of a variation of a portion of an outer liner 340 of FIG. The at least one opening 557 is a plurality of openings 557a, 557b, 557c located within the outer liner 540, each of which defines a secondary combustor outlet 558. In one aspect, the plurality of openings 557a, 557b, 557c are aligned along a circumferential direction CD and are angled relative to the axial direction AD. The axial orientation angle (denoted as "β") is the amount that the at least one opening 557 is rotated from the axial direction AD toward the circumferential direction CD.

[0080] The orientation and location of the plurality of discrete small burners 334 may embody any variation, including Figure 7 , Figure 8 and Fig. 9 Combination of the variations shown. Orientation and position can be adjusted to achieve adequate mixing between the two exhaust gases G1 , G2 .

[0081] The method for controlling nitrogen oxides present in the combustion section 14, 114, 214, 314 described herein includes generating a primary exhaust gas G1 in the primary combustion chamber 46, 146, 246, 346, and generating a secondary exhaust gas G2 in the set of secondary burners 50, 150, 250, 350 including the secondary combustion chamber 54, 154, 254, 354. The method also includes injecting the secondary exhaust gas G2 into the main combustion zone 72, 172, 272 of the primary combustion chamber 46, 146, 246.

[0082] The method may also include providing a first, second or third primary burner angle α as described herein. 1 , α 2 , α 3 The secondary exhaust gas G2 is injected to enhance the mixing of the primary and secondary exhaust gases G1, G2. In addition, the method may include accelerating the flow of the primary fuel / air mixture FA1 and the resulting primary exhaust gas G1 by introducing the secondary fuel / air mixture FA2 via a plurality of discrete small burners 334. The flow of the primary fuel / air mixture FA1 and the resulting primary exhaust gas G1 may also be accelerated by utilizing an annular small burner 34 arranged around the primary burner 32. In addition, as Figure 3 As shown, the proximity of the set of secondary burners 50 accelerates the primary exhaust gas G1.

[0083] The benefit associated with the set of secondary burners in combination with the primary burner and method described herein is that NOx can be reduced even in severe cycles with higher operating air pressures, higher temperatures, higher fuel / air ratios and heating fuel. x Emissions. Typically, higher fuel / air ratios within a combustion system result in higher flame temperatures, which results in higher NO xBy having two combustion chambers within the combustion system, the fuel can be split between these chambers, thereby reducing the fuel / air ratio in each chamber, thereby achieving lower temperatures and therefore lower NO x By directing the combustion products from the secondary combustion into the primary combustion chamber, the O 2 level, thereby further reducing NO x The combustion section in this paper can use 100% H 2 Fuel to operate.

[0084] Although described with respect to a turbine engine, it should be understood that the combustor described herein may be used with a turbine engine having NOx emissions. x It should be understood that the application of the various aspects of the disclosure discussed herein may also be applied to engines having a propeller section or a fan and supercharger section, as well as turbojets and turbine engines.

[0085] To the extent not yet described, the different features and structures of the various embodiments may be used in combination or in place of one another as desired. The fact that a feature is not shown in all embodiments does not mean that it cannot be shown as such, but is done so for the sake of brevity of description. Thus, the various features of the different embodiments may be mixed and matched as desired to form new embodiments, whether or not the new embodiments are explicitly described. All combinations or permutations of the features described herein are covered by the present disclosure.

[0086] This written description uses examples to describe the aspects of the disclosure described herein, including the best mode, and also to enable any person skilled in the art to practice aspects of the disclosure, including making and using any device or system and performing any combined methods. The patentable scope of the various aspects of the disclosure is defined by the claims, and may include other examples that occur to one skilled in the art. These other examples are intended to fall within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims.

[0087] Further aspects are provided by the subject matter of the following clauses:

[0088] A combustion section for a turbine engine, the combustion section comprising: a primary combustor liner, the primary combustor liner comprising an inner liner and an outer liner; a dome wall, the dome wall extending from the inner liner toward the outer liner; a dome inlet, the dome inlet being located in the dome wall and defining a first centerline; a primary combustor, the primary combustor having a primary combustion chamber at least partially defined by the inner liner, the outer liner and the dome wall, the primary combustion chamber having a primary combustor height; and at least one small combustor, the at least one small combustor having a secondary combustion chamber and a small dome inlet, the secondary combustion chamber being fluidically connected to the primary combustion chamber and having a small combustor height; wherein the small combustor height is less than the primary combustor height.

[0089] A combustion section as in any preceding clause wherein the small burner height is in the range of 0% to 60% of the primary burner height.

[0090] A combustion section according to any preceding clause, wherein the at least one small burner is an annular small burner.

[0091] A combustion section as in any preceding clause, further comprising a secondary combustor liner extending axially from said dome wall and terminating in a rear wall, said rear wall extending radially toward said mini-dome inlet an amount equal to said mini-combustor height.

[0092] A combustion section as described in any preceding clause, wherein the outer liner and the rear wall together define at least a portion of the secondary combustion chamber.

[0093] A combustion section as in any preceding clause, wherein the primary combustor height is a radial dimension extending between the secondary combustor liner and the inner liner.

[0094] The combustion section of any preceding clause, further comprising at least one opening extending through the outer liner and located downstream of the dome inlet.

[0095] A combustion section as in any preceding clause, wherein the secondary combustion chamber is fluidly coupled to the primary combustion chamber at the at least one opening.

[0096] A combustion section as in any preceding clause, wherein the primary combustion chamber is annular about an engine centreline of the turbine engine.

[0097] A combustion section according to any preceding clause, wherein the at least one small burner is an annular small burner.

[0098] The combustion section of any preceding clause, wherein the at least one small burner is a plurality of discrete small burners arranged circumferentially about the engine centerline, and the at least one opening is a plurality of openings corresponding to the plurality of discrete small burners.

[0099] A combustion section as in any preceding clause, wherein the plurality of openings are located at the same axial position and are aligned in a circumferential direction.

[0100] A combustion section as in any preceding clause, wherein at least one opening of the plurality of openings is angled relative to an axial direction.

[0101] A combustion section as in any preceding clause, wherein the plurality of openings are axially spaced from one another in the axial direction and are misaligned in the circumferential direction.

[0102] A combustion section as in any preceding clause, wherein the domed inlet defines a first centerline and the mini-dome inlet defines a second centerline, and the first centerline and the second centerline intersect to define a primary burner angle in a radial plane.

[0103] A combustion section as described in any preceding clause, wherein the primary burner angle varies from 90° to 165°.

[0104] A combustion section according to any preceding clause, wherein the dome inlet defines a first centerline and the mini-dome inlet defines a second centerline, and a primary burner length is measured parallel to the first centerline between the dome wall and the primary burner outlet, and a main combustion length is measured parallel to the first centerline from the dome wall to the second centerline, wherein the main combustion length is 5% to 90% of the primary burner length.

[0105] A combustion section as described in any preceding clause wherein the primary burner angle is 90°.

[0106] A combustion section as described in any preceding clause, wherein the primary burner angle varies from 90° to 165°.

[0107] A combustion section as in any preceding clause, further comprising a set of dilution openings in the primary combustor liner.

[0108] A combustion section as in any preceding clause, wherein the set of dilution openings are located in the outer liner.

[0109] A combustion section as in any preceding clause, wherein the set of dilution openings are located in the liner.

[0110] A combustion section as in any preceding clause, wherein the set of dilution openings are located upstream of the at least one small burner.

[0111] A combustion section as in any preceding clause, wherein the set of dilution openings are located downstream of the at least one small burner.

[0112] A combustion section as in any preceding clause, further comprising a set of dilution openings in the small combustor liner.

[0113] A combustion section according to any preceding clause, wherein the dome inlet defines a first centerline and the mini-dome inlet defines a second centerline, and a primary burner length is measured parallel to the first centerline between the dome wall and the primary burner outlet, and a main combustion length is measured parallel to the first centerline from the dome wall to the second centerline, wherein the main combustion length is 5% to 90% of the primary burner length.

[0114] A turbine engine comprises a compressor section, a combustion section and a turbine section in a serial flow arrangement along a centerline of the engine, the combustion section comprising: a primary combustor liner, the primary combustor liner comprising an inner liner and an outer liner; a dome wall, the dome wall extending from the inner liner toward the outer liner; a dome inlet, the dome inlet being located in the dome wall and defining a first centerline; a primary combustor, the primary combustor having a primary combustion chamber at least partially defined by the inner liner, the outer liner and the dome wall, the primary combustion chamber having a primary combustor height; and at least one small combustor, the at least one small combustor having a secondary combustion chamber and a small dome inlet, the secondary combustion chamber being fluidically connected to the primary combustion chamber and having a small combustor height; wherein the small combustor height is in the range of 0% to 60% of the primary combustor height.

[0115] A turbine engine according to any preceding clause, wherein said at least one small burner is an annular small burner.

[0116] A turbine engine as claimed in any preceding clause, wherein said at least one small combustor is a plurality of discrete small combustors.

[0117] A combustion section as in any preceding clause, further comprising a set of dilution openings in the primary combustor liner.

[0118] A combustion section as in any preceding clause, wherein the set of dilution openings are located in the outer liner.

[0119] A combustion section as in any preceding clause, wherein the set of dilution openings are located in the liner.

[0120] A combustion section as in any preceding clause, wherein the set of dilution openings are located upstream of the at least one small burner.

[0121] A combustion section as in any preceding clause, wherein the set of dilution openings are located downstream of the at least one small burner.

[0122] A combustion section as in any preceding clause, further comprising a set of dilution openings in the small combustor liner.

[0123] A method for controlling nitrogen oxides present in a combustion section includes generating a primary exhaust gas in a primary combustion chamber and generating a secondary exhaust gas in a set of secondary burners including a set of secondary combustion chambers.

[0124] A method as described in any preceding clause, further comprising injecting the secondary exhaust gas into a main combustion zone of the primary combustion chamber.

[0125] A method as claimed in any preceding clause, further comprising enhancing mixing of the primary exhaust gas and the secondary exhaust gas by injecting the secondary exhaust gas at a first, second or third primary angle.

[0126] A method as in any preceding clause, further comprising accelerating the flow of the primary fuel / air mixture and the primary exhaust gas produced therefrom by introducing the secondary fuel / air mixture through discrete small burners.

[0127] A method according to any preceding clause, further comprising accelerating the flow of the primary fuel / air mixture and the primary exhaust gas produced thereby by utilizing an annular small burner arranged around the primary burner.

[0128] A method according to any preceding clause, further comprising accelerating the flow of a primary fuel / air mixture and primary exhaust gas produced thereby by positioning said set of secondary burners 50 in close proximity to said primary combustion chamber.

Claims

1. A combustion section for a turbine engine, characterized in that: The combustion section comprises: a primary combustor liner, the primary combustor liner comprising an inner liner and an outer liner; a dome wall extending from the inner liner toward the outer liner; a dome inlet located in the dome wall and defining a first centerline; a primary combustor having a primary combustion chamber defined at least in part by the inner liner, the outer liner, and the dome wall, the primary combustion chamber having a primary combustor height; and at least one small burner having a secondary combustion chamber and a small dome inlet, the secondary combustion chamber being fluidly coupled to the primary combustion chamber and having a small burner height; The height of the small burner is smaller than the height of the primary burner.

2. The combustion section according to claim 1, characterized in that: in, The small burner height is in the range of 0% to 60% of the primary burner height.

3. The combustion section according to claim 2, characterized in that in, The at least one small burner is an annular small burner.

4. The combustion section according to claim 3, characterized in that Further included is a secondary combustor liner extending axially from the dome wall and terminating in an aft wall that extends radially toward the mini-dome inlet an amount equal to the mini-combustor height.

5. The combustion section according to claim 4, characterized in that in, The outer liner and the rear wall together define at least a portion of the secondary combustion chamber.

6. The combustion section according to claim 5, characterized in that in, The primary combustor height is a radial dimension extending between the secondary combustor liner and the inner liner.

7. The combustion section according to claim 2, characterized in that: Further included is at least one opening extending through the outer liner and located downstream of the dome inlet.

8. The combustion section according to claim 7, characterized in that in, The secondary combustion chamber is fluidly coupled to the primary combustion chamber at the at least one opening.

9. The combustion section according to claim 8, characterized in that in, The primary combustion chamber is annular about an engine centerline of the turbine engine.

10. The combustion section according to claim 9, characterized in that in, The at least one small burner is an annular small burner.

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